We Keep Coding

For spring-batch transaction is not getting rolled back after exception

I am working on a spring-batch, where after reader and processor, writer is responsible to populate data to DB. Writer is calling Service which internally calls DAO layer. In method insertToDB() if some exception occurs the transaction is not being rolled back. PSB my code.
public class MyWriter{
#Autowired
private MyService myService;
#Override
public void write(List<? extends MyBO> list) {
try{
for(MyBO bo: list){
myService.insert(bo);
}
}
catch(Exception e){
log.error("Cant write to DB")
}
}
public class MyService{
#Autowired
private TableOneDAO tableOneDao;
#Autowired
private TableTwoDAO tableTwoDAO;
#Autowired
private TableThreeDAO tableThreeDAO;
public void insert(MyBO bo){
try{
// do other stuff of processing bo and create entity
MyEntityTableOne myentity1 = getEntityT1(bo);
MyEntityTableTwo myentity2 = getEntityT2(bo);
MyEntityTableThree myentity3 = getEntityT3(bo);
insertToDB(myEntity1,myEntity2,myEntity3);
}
catch(Exception e){
log.error("Error occured.");
throw new MyException("Error Blah blah occured");
}
}
#Transactional(value = "txn1")
public void insertToDB(MyEntityTableOne entity1, MyEntityTableTwo entity2, MyEntityTableThree entity3) {
try{
tableOneDao.insert(entity1);
tableTwoDAO.insert(entity2);
tableThreeDAO.insert(entity3);
}
catch(Exception e){
log.error("Error occured during insert to DB");
throw new MyException("Error Blah blah occured during DB insert");
}
}
The code goes to the catch block, but doesn't rollback records. If some error occurs during insert of Table2 then entry for Table1 is not rolled-back. And if occurs during table3 insertion then table1 and table2 records are not rolled-back.
If I move the #Transactional annotation to insert() method it works fine. What is root cause of this issue. What I have to do if I want to have transaction only on insertToDB() method.

I am trying to make it simple: To support #Transactional spring wraps the implementing class into a so called proxy and surrounds the method call / class with the transactional logic.
Now you are calling the #Transactional annotated method within the same class. Therefore the proxy is not invoked and the transactional does not work. When moving the annotation to your insert method you are invoking the method from outside of the class which means you invoke the method against the proxy.
Thats a limitation of Spring AOP (?) I think.
You can do something like following to achieve what you want:
public class MyService{
#Ressource
private MyService self;
...
self.insertToDB(myEntity1,myEntity2,myEntity3)

Your item writer will be already called in a transaction driven by Spring Batch and that you can configure at the step level by providing the transaction manager and transaction attributes. So there is no need to use #Transactional in the downstream service used by the writer.
You need to remove that annotation from MyService and it should work as expected.

Transactional doesn't roll back on checked exception in Spring Boot with Data JPA

I have a ProcessRecon usecase class with a single method named execute. It saves an entity Reconciliation using paymentRepository.saveRecon and calls a web service as part of acknowledgement using paymentRepository.sendReconAck.
Now there's a chance that this external web service might fail in which case I want to rollback the changes i.e. the saved entity. Since I am using Unirest, it throws UnirestException which is a checked exception.
There are no errors on the console but this will probably be helpful [UPDATED].
2020-08-20 17:21:42,035 DEBUG [http-nio-7012-exec-6] org.springframework.transaction.support.AbstractPlatformTransactionManager: Creating new transaction with name [com.eyantra.payment.features.payment.domain.usecases.ProcessRecon.execute]:PROPAGATION_REQUIRED,ISOLATION_DEFAULT,-com.mashape.unirest.http.exceptions.UnirestException
...
2020-08-20 17:21:44,041 DEBUG [http-nio-7012-exec-2] org.springframework.transaction.support.AbstractPlatformTransactionManager: Initiating transaction rollback
2020-08-20 17:21:44,044 DEBUG [http-nio-7012-exec-2] org.springframework.orm.jpa.JpaTransactionManager: Rolling back JPA transaction on EntityManager [SessionImpl(621663440<open>)]
2020-08-20 17:21:44,059 DEBUG [http-nio-7012-exec-2] org.springframework.orm.jpa.JpaTransactionManager: Not closing pre-bound JPA EntityManager after transaction
2020-08-20 17:22:40,020 DEBUG [http-nio-7012-exec-2] org.springframework.orm.jpa.support.OpenEntityManagerInViewInterceptor: Closing JPA EntityManager in OpenEntityManagerInViewInterceptor
What I see at the moment is that entity gets pushed to database even if there's a UnirestException. But I expect no data be saved to database.
I am using Spring Boot 2.3.3 with MySQL 5.7. This is the code I have for it.
ProcessRecon.java
#Usecase // this custom annotation is derived from #service
public class ProcessRecon {
private final PaymentRepository paymentRepository;
#Autowired
public ProcessRecon(PaymentRepository paymentRepository) {
this.paymentRepository = paymentRepository;
}
#Transactional(rollbackFor = UnirestException.class)
public Reconciliation execute(final Reconciliation reconciliation) throws UnirestException {
PaymentDetails paymentDetails = paymentRepository.getByReqId(reconciliation.getReqId());
if (paymentDetails == null)
throw new EntityNotFoundException(ExceptionMessages.PAYMENT_DETAILS_NOT_FOUND);
reconciliation.setPaymentDetails(paymentDetails);
Long transId = null;
if (paymentDetails.getImmediateResponse() != null)
transId = paymentDetails.getImmediateResponse().getTransId();
if (transId != null)
reconciliation.setTransId(transId);
if (reconciliation.getTransId() == null)
throw new ValidationException("transId should be provided in Reconciliation if there is no immediate" +
" response for a particular reqId!");
// THIS GETS SAVED
Reconciliation savedRecon = paymentRepository.saveRecon(reconciliation);
paymentDetails.setReconciliation(savedRecon);
// IF THROWS SOME ERROR, ROLLBACK
paymentRepository.sendReconAck(reconciliation);
return savedRecon;
}
}
PaymentRepositoryImpl.java
#CleanRepository
public class PaymentRepositoryImpl implements PaymentRepository {
#Override
public String sendReconAck(final Reconciliation recon) throws UnirestException {
// Acknowledge OP
return sendAck(recon.getRequestType(), recon.getTransId());
}
String sendAck(final String requestType, final Long transId) throws UnirestException {
// TODO: Check if restTemplate can work with characters (requestType)
final Map<String, Object> queryParams = new HashMap<String, Object>();
queryParams.put("transId", transId);
queryParams.put("requestType", requestType);
logger.debug("{}", queryParams);
final HttpResponse<String> result = Unirest.get(makeAckUrl()).queryString(queryParams).asString();
logger.debug("Output of ack with queryParams {} is {}", queryParams, result.getBody());
return result.getBody();
}
#Override
public Reconciliation saveRecon(final Reconciliation recon) {
try {
return reconDS.save(recon);
}
catch (DataIntegrityViolationException ex) {
throw new EntityExistsException(ExceptionMessages.CONSTRAINT_VIOLATION);
}
}
}
ReconciliationDatasource.java
#Datasource // extends from #Repository
public interface ReconciliationDatasource extends JpaRepository<Reconciliation, Long> {
List<Reconciliation> findByPaymentDetails_User_Id(Long userId);
}

To make annotations work you have to use interfaces instead of classes for dependency injection.
interface ProcessRecon {
Reconciliation execute(final Reconciliation reconciliation)
throws UnirestException;
}
Then
#Usecase
public class ProcessReconImpl implements ProcessRecon {
private final PaymentRepository paymentRepository;
#Autowired
public ProcessReconImpl(PaymentRepository paymentRepository) {
this.paymentRepository = paymentRepository;
}
#Transactional(rollbackFor = UnirestException.class)
public Reconciliation execute(final Reconciliation reconciliation) throws UnirestException {
//method implementation...
}
}
Usage
#Autowired
ProcessRecon processRecon;
public void executeServiceMethod(Reconciliation reconciliation) {
processRecon.execute(reconciliation)
}
This way you have got proxy of ProcessReconImpl with provided by annotations additional functionality.

I assumed the default engine for the tables would be InnoDB but to my surpise, the tables were created using MyISAM engine which doesn't support transactions.
I resolved the problem by using the below property as suggested here
spring.jpa.database-platform=org.hibernate.dialect.MySQL5InnoDBDialect
instead of
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect
That was the only change required. Thanks!

How to do Rollback with Transactional Annotation

I am trying to do Transactional Rollback in my methods. Intentionally i am making the insert fails to find out . But i don't see its getting rolled back . Please help what i am missing.
#Service
public class ModesService implements IModesService{
ChargeRuleDao chargeRuleDao;
public ModesService(ChargeRuleDao chargeRuleDao){
this.chargeRuleDao = chargeRuleDao;
}
#Override
#Transactional(propagation = Propagation.REQUIRED)
public void process(ChargeRule chargeRule){
chargeRuleDao.deleteShippingChargeAttr(shippingChargeRuleID);
chargeRuleDao.deleteShippingCharge(shippingChargeRuleID);
chargeRuleDao.deleteShippingChargeDest(shippingChargeRuleID);
//Delete
chargeRuleDao.insertShipChargeFeedRule(chargeRule);
}
In DAOImpl class i have methods like below for all deletions and insertion.
#Override
public int deleteShippingChargeAttr(String test) {
MapSqlParameterSource params = new MapSqlParameterSource();
params.addValue("ABC" "ABC", Types.VARCHAR);
return jdbcTemplate.update(DELETE_QUERY, params);
}

You may try #Transactional(rollbackFor = XYZException.class).
XYZException should be an exception which should wrap all the exceptions/exception for which you want to rollback the transaction.

Rollback occurs by default for every unchecked exception. That means you need to throw some type unchecked exception, like for example
throw new NullPointerException();
in your insertShipChargeFeedRule(chargeRule);
more about #Transactional here https://javamondays.com/spring-transactions-explained/

Transaction partially committing or rolling back

I am facing some issue with transactions configured in my code.
Below is the code with transactions which writes data to DB.
Writer.java
class Writer {
#Inject
private SomeDAO someDAO;
#Transactional(propagation = Propagation.REQUIRES_NEW)
public void write(){
this.batchWrite();
}
private void batchWrite () {
try {
someDAO.writeToTable1(true);
} catch(Exception ex) {
someDAO.writeToTable1(false);
}
someDAO.writeToTable2();
}
}
SomeDAO.java
class SomeDAO {
#Inject
private JdbcTemplate JdbcTemplate;
public void writeToTable1(boolean flag) {
// Writes data to table 1 using jdbcTemplate
jdbcTemplate.update();
}
pulic void writeToTable2() {
// Writes data to table 2 using jdbcTemplate
jdbcTemplate.update();
}
}
Here data is getting stored into table 1 properly but sometimes, table 2 is getting skipped.
I am not sure how this is happening as both the tables have been written within same transaction.
Either transaction is partially committing the data or partially rolling back.
I have doubt that in the SomeDAO class I am injecting JdbcTemplate object which is creating new connection instead of using existing connection of transaction.
Can anyone please help me here?

Try binding a Transaction Manager bean having your jdbcTemplate inside #Transactional:
//Create a bean
#Bean
public PlatformTransactionManager txnManager() throws Exception {
return new DataSourceTransactionManager(jdbcTemplate().getDataSource());
}
And then use this transaction manager in #Transactional("txnManager").

UnexpectedRollBackException in Spring inner transaction

I have two classes:
#Service
#Transaction
class A {
public void method1() {
private B;
try {
save1()
b.method2()
} catch (SqlException e) {
doSomeThing();
}
#Autowired
public setB(){
this.B = B;
}
}
}
#Service
class B {
#Transactional(propagation = Propagation.REQUIRES_NEW, rollbackFor = Exception.class)
public void method2(){
save2()
throw new SqlException();
}
}
I got an SqlException as expected, but also an UnexpectedRollBackException, and the program stops.
I want to know why the data persisted by save2() is not rolled back?
Is it a problem with outer transaction?
UPDATE: I tried catching UnexpectedRollBackException in class A and everything works fine. But I still need some kind of explanation why I get the exception? I suppose the outer transaction should be suspended when the inner transaction begins, so why the rollback is unexpected for the outer transaction?
Thanks.

First of all: you are not injecting the instance of B into class A via spring. i.e. your b is not managed by spring => this leads to the behaviour: Spring is ignoring the #Transactional annotation on method.
Second if you don't want to rollback on SqlException you have to specify noRollbackFor=SqlException.class
UPDATE: after clarification, the call is happening on managed bean. But the problem that expected behaviour - transaction inside of transaction is not supported in general by the transaction management system out of the box. https://docs.spring.io/spring/docs/4.3.11.RELEASE/javadoc-api/org/springframework/transaction/annotation/Propagation.html#REQUIRES_NEW
Unless the details on that system are provided it is impossible to step forward. Out of content the NESTED transaction propagation could be better, then REQUIRES_NEW, because it is making a rollback point for the external transaction and starts new one.

I have a simliar scenario like this and resolved it using propagation = Propagation.NESTED from where the second method is calling. rewrite the code as mentioned below and try.
#Service
class A {
#Transactional(rollbackFor = { HibernateException.class}, propagation = Propagation.NESTED)
public void method1() {
private B;
try {
save1()
b.method2()
} catch (SqlException e) {
doSomeThing();
}
#Autowired
public setB(){
this.B = B;
}
}
}
Note: Transactional is used in method level for class A with propagation nested . Class B shown below.
#Service
class B {
#Transactional(rollbackFor = {Exception.class}, propagation = Propagation.REQUIRED)
public void method2(){
save2()
throw new SqlException();
}
}
This has resolved the issue in my case.